Poor maternal dietary quality in the 1st trimester of pregnancy can alter the intrauterine nutritional environment and adversely affect placental development and subsequent fetal development and growth. The early months of pregnancy, when the placenta undergoes rapid development, are critical because nutrients must be present in proper balance for successful blastocyst implantation. Inadequate placental development can result in a diminished supply of nutrients to the fetus, thus inhibiting proper growth and leading to intrauterine growth restriction. Thus a pregnant woman's dietary quality, particularly in the first trimester of pregnancy, is a key factor affecting pregnancy outcomes. Dietary quality in pregnancy is determined through an integrative assessment of nutritional intake that is compared to recommendations for pregnancy established by U.S. Department of Agriculture and the Institute of Medicine. Decades of nutrition research has focused on the effects of isolated nutrients on pregnancy outcomes;however the complex metabolic interactions among nutrients make it difficult to isolate the effects of any single nutrient. Yet, minimal research exists that assesses overall dietary quality or explores the effects of potentially modifiable factors on low- income women's dietary intake during the critical first trimester. A observational design will be used to explore the relationships among modifiable and contextual factors, and dietary quality in the first trimester of pregnancy. The specific aims are to: 1) examine the relationships of modifiable maternal factors (stress, depression, social support, emotional eating, nutritional knowledge, eating habits) and contextual maternal factors (ethnicity, pre-pregnant BMI, pregnancy-spacing, pregnancy intendedness, nausea and vomiting) to dietary quality;and 2) explore the relationships of dietary quality and selected nutrition biomarkers to placental development. A sample of 132 low-income women in their first trimester of pregnancy will be recruited. Participants will complete surveys that assess contextual and modifiable factors (demographics, depression, stress, social support, eating habits, and nutrition knowledge) that may influence dietary quality and have blood drawn to test biological measures of dietary quality and placental development. Within two weeks after initial recruitment, three 24-hour dietary recalls will be obtained by telephone using the Multiple- Pass Method incorporated within the Nutrition Data System for Research (NDSR) program. Descriptive, correlation, and regression analysis will be conducted to address the specific aims of the study. Examining the influence of contextual and modifiable factors on dietary quality and placental development in the 1st trimester can identify maternal attributes that may be modifiable during the remainder of the pregnancy through targeted interventions and public health strategies and campaigns. Data from this exploratory study will guide future development of interventions that can be translated into practice, which may lead to improved obstetric and fetal outcomes and women's long-term health. Public Health Relevance: Examining low-income women's dietary quality in the first trimester of pregnancy and the factors that produce and/or inhibit it during this crucial period of fetal development can identify maternal behaviors that may be modifiable during the remainder of pregnancy. Data from this study can be used to guide the development of targeted interventions that may be practical in this vulnerable population. More effective targeted strategies initiated within this narrow window of time may reduce the number of low birth weight infants and improve obstetrical outcomes.